1. Field of the Invention
This invention relates generally to the field of archery bow sights, and more particularly to a modular laser range finder apparatus adapted to be mounted and integrated into a bow sight.
2. Description of the Related Art
Bow sights have long been known for use with archery bows. They range from simple pin markers to peep sights, to vertically aligned series of horizontal pins mounted in a generally annular frame to protect the pins. These latter multi-pin sights have proliferated in the last few years, especially in the hunting arena, where the distance to a target or target animal can vary as much as from 10 to 60 yards. In the bow hunting situation, the trajectory of an arrow must be accurately predicted if an archer is to have any confidence in accurate shot placement. Since the typical range to a target may vary substantially, it is critical that a good estimate of the distance for a particular shot be known with some degree of accuracy. The archer typically has to premeasure or step off the distance to an anticipated target location from the archer's tree stand, blind, or other shooting location. Alternatively he or she must simply guess as to the appropriate distance in order to compensate for the effects of gravity on an arrow in flight to the target. In the past, there have been few tools to aid the archer in this endeavor.
One such tool has been a multiple pin sight. Normal multi-pin sights simply have several brass aiming pins which stick out horizontally from a vertical frame mounted in front of the hand grip on the bow. Each pin corresponds to a particular target distance. The archer visually estimates the appropriate range and then sights to the target using the appropriate aiming pin corresponding to that range. Recently an enhancement to the multi-pin sight has been introduced. This sight has light gathering fiber optic filaments which provide a self powered illuminated dot that the archer sees at the end of each aiming pin. These fiber optic multiple pin sights have greatly improved the utility of such sights in low light or low contrast lighting situations.
To address the accuracy of range estimating, a laser rangefinder sight has been marketed by Bushnell of Overland Park Kans. This rangefinder system has a laser range finding instrument mounted above a multiple pin bow sight. The rangefinder is actuated by a switch that is pressed by the archer's finger when the bow sight is aimed at a target. While the switch is depressed, the rangefinder senses the target. The laser rangefinder then calculates and displays the distance to the target to the archer. The archer then chooses which of several sighting pins to align with the target based on the distance displayed. For example, if the archer has preset the pins to distances of 10, 20, 30, 40, and 50 yards, the archer would choose the pin closest to the displayed target distance. In one model, the Bushnell laser rangefinder is integral with the multiple pin sight. The entire sight may be removed from the bow and used as a hand held distance measurement device. In another model, the rangefinder is modular and may be removed from the bowsight for use as a hand held distance measuring device.
One of the major disadvantages with the Bushnell rangefinder is that this laser rangefinder only indicates the range when aimed, line of sight, at the target. Thus, after the range is determined, the archer must disregard the rangefinder reading while actually aiming the bow, i.e. raising the bow such that the appropriate distance pin of the bow sight is aligned with the target. The archer may easily mistakenly choose the incorrect pin with which to aim at the target, resulting in a missed shot. Another disadvantage is that this rangefinder does not correlate the measured range directly with the particular sight pin being used.
Therefore there is a need for a versatile archery laser rangefinder directly indicates the correct target range to the archer even as the arrow is being aimed at the target and elevation compensated for the actual target distance. There is further a need for an integrated bow sight which automatically tells the archer which of a plurality of range pins to utilize when aiming at a particular target so as to avoid the potential for using the wrong pins.